I use this cart to wheel my kayak just 2 short blocks from my garage to a smooth landing ramp into the LA river. Sure it sees a couple bumps in the pavement along the way, but nothing off-road. Even with near-ideal conditions.. THE WHEELS FALL OFF AT AN ALARMING RATE. Yes, you read correctly, I will be dragging my boat down the street and all of a sudden the cart will collapse as the wheel falls off. The design simply does not work as intended, which will probably not surprise you when you see that just a little ramped piece of plastic and a spring is all that holds the wheels onto the axle.
Luckily I have managed to find the little plastic piece and metal spring each time a wheel has fallen off, but it's only a matter of time before I have a breakdown and lose one of those little pieces and at that point I will be totally hosed.